Introduction to performance handicaps

How does the YV Performance Handicap System work?

Some recent discussion of performance handicap changes on Wednesday evening races prompted me to offer some explanation of the YV Performance Handicap System and how handicaps are recalculated.

All boats at RYCV have a performance handicap.

By definition this performance handicap indicates the performance of each boat in the Club relative to other boats in the Club.

Please do not confuse a measurement rating (such as AMS or IRC) with a performance handicap. Ratings are calculated from measurements of the boats hull, rig and sails, and once calculated will not change unless changes are made to the boat, whilst a boats performance handicap will probably change after each race.

Performance handicaps are generated and recalculated in accordance with the Yachting Victoria Performance Handicap Rules.

Since September 2014, Royals has been using a software package called TopYacht. This has replaced the system we have used for many years, namely PAT. TopYacht calculates the results of each race and also recalculates the handicap for each boat for the next race.

When a boat enters a club race, it will be allocated a performance handicap for that race, called its Allocated Handicap (AH). This AH will be taken from the TopYacht database or will be supplied by the Club Handicapper).

This performance handicap is a single figure Time Correction Factor (TCF) and is used to convert a boats elapsed race time to a corrected time. Thus if a boat takes 100 minutes to complete the race and its Performance Handicap (or TCF) was 0.75 the its corrected time (CT) will be 75 minutes (100 x 0.75).

The boat with the lowest corrected time (CT) is the race winner.

After each Club race the TopYacht programme will calculate data for each boat, namely

1. The corrected time (the boat with the lowest CT being the winner).

2. The back calculated handicap (BHC). This is the handicap that each boat actually achieved in the race. Boats in the top half of the results list will have BCH values above their AH

and boats at the bottom half below their AH.

3. The Calculated Handicap (CHC) for each boat. This is the handicap for each boat in its next race.

The CHC is calculated as follows

CHC = 2/3AH+1/3 BCH

Thus for example if the AH was 0.800 and the BCH was 0.815, then

CHC= 0.8*2/3+0.815*1/3=805

However if you read the YV Handicap Rules, you will note terms such a LBCH, LBCHU, LBCHL and LBCHD.

These are

Abbreviation

Handicap

Clamp

LBCH

Limited Back Calculated Handicap

4%

LBCHU

Limited Back Calculated Handicap Upper

4%

LBCHL

Limited Back Calculated Handicap Lower

4%

LBCHD

Limited Back Calculated Handicap Discard

8%

The YV Rules have recognised that on some occasions other factors come into race results. There could be a drop in wind soon after part of the fleet finishes or same boats could have a problem on the water but choose to finish. Thus we use "clamps". Clamps limit the change of the Back Calculated Handicap (BCH) and produce a Limited Back Calculated Handicap (LBCH).

Currently the clamps are 4% on handicaps and 8% on a discard. Thus if the BCH is greater than 104% or between 96% and 92% the BCH is limited to 104% and 96% respectively (clamping the BCH to 4%). However if the BCH is less than 92% of the AH then the result is discarded for handicap recalculation purposes and the CHC remains unchanged.

To illustrate how the recalculation system works I have calculated the results for the Wednesday evening race of 2nd February 2013

SAMPLE CALCULATON OF HANDICAPS

(Wednesday evening race 2nd February 2013)

BCH

BCH used

AH

Value

%

%

Value

CHC

R727

GALAXY

762

826

108

LBCHU

104%

792

772

R362

DUCKMOBILE

776

814

105

LBCHU

104%

807

786

R6257

MAINSTAY

782

819

105

LBCHU

104%

813

792

R18

MONEYPENNY

783

816

104

BCH

actual

816

794

H6336

THE BOOKMAKER

817

847

104

BCH

actual

847

827

R2

CIRCE

769

784

102

BCH

actual

784

774

1210

MIKA

760

764

101

BCH

actual

764

761

7018

JUST QUIETLY

784

786

100

BCH

actual

786

785

R363

TOP GUN

860

860

100

BCH

actual

860

860

R67

ENESEAY

803

800

100

BCH

actual

800

802

R6198

NEXT MOMENT

819

813

99

BCH

actual

813

817

R880

ALIEN

819

808

99

BCH

actual

808

815

R175

PARAGON

755

734

97

BCH

actual

734

748

R650

THE STIGS AUDI ETC

862

823

95

LBCHL

96%

828

851

H1010

IKON

994

945

95

LBCHL

96%

954

981

R149

COUSIN IT

809

768

95

LBCHL

96%

777

798

H8118

MERLION

842

784

93

LBCHL

96%

808

831

R35

LAURELLE

838

774

92

LBCHL

96%

804

827

R1121

EXECUTIVE DECISION

882

798

90

LBCHD

AH

882

882

This sample calculation illustrates all the workings of the YV Performance handicap calculations, namely

a. Galaxy, Duckmobile and Mainstay all had BCH values greater than 104%, thus their BCH was clamped at 104%.

b. Moneypenny, The Bookmaker, Circe, Mika, Just Quietly, Top Gun, Eneseay, Next Moment, Alien and Paragon all had BCH values between 96% and 104% and thus their actual BCH was used.

c. The Stigs Audi, Ikon, Cousin It, Merlion, and Laurelle all had BCH values between 96% and 92% and thus their BCH was clamped at 96%.

d Executive Decision had a bad race and the result was discarded because the BCH was less than 92% (note, although his CHC was noted as 870 in the results, this was corrected at a later date).

This is how the YV Performance System works and how results are recalculated.

On a historical note, performance handicap calculations have changed over the years. In the 1960's boats that came first, second or third had their handicap increased by a fixed %, this later changed to recording the boats last 8 BCH's, discarding the best and two worst results and averaging the remaining 5. The change to the current method (as described above) has been used for about 4 years.

The current recalculation method is more immediately responsive to changes in the boats performance and requires fewer results for a boat to have a valid handicap.

If you have any issues, please contact the author in the first instance and I can usually answer them. The Performance Handicap System has been operating in its current form for about 60 years.

It is not perfect, if it were we would have all boats tied for first place each race.

I always welcome constructive comment and/or criticism, and particularly if you can see a way we might improve what we have.